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New Book Chronicles the Great Lakes’ History and Threats

In his book “The Death and Life of the Great Lakes,” author Dan Egan chronicles the history of the world’s largest group of freshwater lakes as well as the natural and man-made dangers threatening it.

The Great Lakes account for about 21 percent of the Earth’s surface freshwater and provide drinking water to tens of millions of people living in the Great Lakes Basin, or the land surrounding the lakes.

In his book, Egan, who covers the Great Lakes for the Milwaukee Journal Sentinel, details several invasive species that have negatively altered the lakes’ ecosystem.

For instance, the waters of the Great Lakes have become noticeably clearer – but that isn’t necessarily a good thing.

Zebra and quagga mussels first spotted in the Great Lakes nearly 30 years ago have devoured vast amounts of plankton, outcompeting native species for the aquatic food.

“These mussels have fundamentally rewired the way energy flows through the lakes and stripped out the plankton, upon which the food web is built,” Egan said. “But nobody could’ve conceived of quagga and zebra mussels before they arrived, so the biggest threat is what’s coming next that we haven’t heard of.”

Many invasive species, like the voracious Asian carp, have entered or are close to entering the Great Lakes via man-made waterways like the Chicago Sanitary and Ship Canal, which links the lakes to the Mississippi River System, and the St. Lawrence River Seaway, which connects them to the Atlantic Ocean.

Egan also touches on the volatile effect climate change has on the Great Lakes’ water levels and the perilous prospect of foreign actors located outside the Great Lakes River Basin siphoning off freshwater.

Funding to help clean and protect the Great Lakes may be off the table, further throwing its future into jeopardy.

President Donald Trump’s proposed budget, which is pending Congressional approval, slashes $300 million in annual funding for the Great Lakes Restoration Initiative, a federal program started in 2010 that works to restore the lakes’ natural habitat and keep invasive species out of the lakes.

In 1957 legendary CBS newsman Walter Cronkite—lauded as the most trusted man in America—stared into the camera and told viewers that the “greatest engineering feat of our time” was under way. He wasn’t talking about the Soviet Union rocketing the stray dog Laika into orbit, or that year’s development of the first wearable pacemaker, or the recent opening of the United States’ first commercial atomic power plant. He was talking about humans “conquering” nature on a scale and in a fashion never before attempted.

“Right now the greatest concentration of heavy machinery ever assembled—over 3,000 pieces of equipment—are at work on one of the greatest projects in the history of mankind,” Cronkite said as he stood in front of a map of the deep blue Great Lakes and the even deeper blue Atlantic Ocean. He fixed his eyes on the camera and spoke boldly of a construction project that would, in effect, do no less than move the Atlantic Ocean more than 1,000 miles inland, to the middle of North America.

The idea was to scrape and blast a navigation channel along and through the shallow, tumbling St. Lawrence River that flows from the Great Lakes out to the ocean in a manner that would allow giant freighters to steam from the East Coast into the five massive freshwater inland seas. This manmade nautical expressway, as narrow as 80 feet in places and, in one particularly tight section, crossing over a roadway, would open up some 8,000 miles of U.S. and Canadian coastline to ships from around the world. The hope was that essentially landlocked Great Lakes cities like Chicago, Cleveland, Detroit and Toronto would blossom into global ports to rival commercial hubs such as New York, Rotterdam and Tokyo.

The project, Cronkite told his viewers, was big, big as “reshaping a continent, completing the job nature had begun thousands of years ago—of creating an eighth sea . . . a sea of opportunity!”

More than a half century later, the hoped-for flood of global cargo has yet to roar into the lakes from overseas, but something else has— an environmental scourge whose scope and costs are spreading by the day. The St. Lawrence Seaway, you see, didn’t conquer nature at all.

It unleashed it in the form of an ecological catastrophe unlike any this continent has seen.

IT IS HARD TO FAULT CRONKITE TODAY FOR HIS OPTIMISM, BECAUSE the nautical magic he and so many others were convinced the Seaway would uncork had happened before. Some six million years ago, the Mediterranean Sea itself was isolated from the Atlantic Ocean. It was little more than a salty puddle at the bottom of a vast basin laced with dusty canyons, some of which plunged more than a mile below sea level. This arid wasteland had previously been a massive Atlantic Ocean inlet, as it is today. But then a tectonic fusion of Africa and Europe created a narrow strip of land that plugged the Mediterranean’s connection to the Atlantic Ocean near what is now the Strait of Gibraltar. This pretty much killed the ancient Mediterranean Sea, which owed its existence to a constant inflow of ocean water, just as it does today. With that Atlantic input plugged, the rivers feeding the suddenly land- locked basin proved too feeble to keep pace with evaporation, and the sea all but vanished in about 1,000 years—which is to say, geologically speaking, nothing. But on a human scale the sea would have shrunk at an imperceptibly slow pace; each day on its shores would have seemed exactly like the last.

The Mediterranean Sea basin, one popular theory goes, remained in this desiccated state for the next 700,000 years or so. But about 5.3 million years ago a seismic hiccup at the Gibraltar isthmus opened a small channel for the Atlantic Ocean to begin dribbling back in. The trickle soon turned to a torrent, many of today’s geologists reckon, as an ever-widening and deepening tongue of saltwater roared back into the basin with incomprehensible speed, volume and violence. It carried the equivalent of some 40,000 Niagara Falls flowing at about 90 miles per hour. This all happened around the time our ancestors’ thigh bones formed a bridge with their hips strong enough to allow them to walk upright and, perhaps—if any of them happened to be in the area at the time the Atlantic came roaring back—to run.

At the peak of the Atlantic cascade the new Mediterranean Sea was rising at a rate of about 30 feet per day, and geologists hypothesize that the entire basin—roughly 2,500 miles long and 500 miles wide—could have filled to sea level in less than three years.

The Mediterranean’s revival indubitably wrought devastation for the terrestrial creatures scratching out a life in the scorched basin, including dwarf elephants and hippos. But it proved a boon for the dolphins and fish and even microscopic life sucked in from the North Atlantic. The devastation also, eventually, opened the door for civilization to blossom, because the Mediterranean Sea connected cultures and economies in a manner that would not have been possible had the basin remained a desert. Today the Mediterranean gives 21 countries from three continents nautical access to each other and—thanks to the eight-mile-wide Strait of Gibraltar carved by the Atlantic Ocean—to the rest of the globe.

About 7,600 years ago, the Black Sea was isolated from the Atlantic Ocean. It was an inland freshwater lake cut off from the Mediterranean Sea to the west by a spit of land called the Bosporus Valley. At the peak of the last ice age some 20,000 years ago, so much of the earth’s water was tied up in glaciers that, according to some estimates, sea level was nearly 400 feet lower than it is today. As the glaciers melted and the oceans rose, so did the Mediterranean. And eventually the Mediterranean did to the Black Sea what the Atlantic Ocean had done to it more than 5 million years earlier: it came crashing in.

The speed with which this happened, as well as its scale, is a matter of some controversy, but a popular hypothesis is that the salty water tumbled in at a force equivalent to 200 Niagara Falls. The inundation that submerged some 60,000 square miles under hundreds of feet of water happened so swiftly—some geologists estimate the sea was rising at a rate of about six inches per day—that it would have sent scrambling any humans who had found the lakeshore an oasis in an otherwise parched landscape. The salty water also ravaged the lake’s freshwater biological community, rendering extinct the species that could not adapt and sending others—like the Black Sea sturgeon— darting for safety in the freshwater rivers that still feed the sea today.

To call this a natural disaster of biblical proportions is what two Columbia University geophysicists did when they published a book in 1998 titled Noah’s Flood. They argue that this geologic event, which is commonly known as the Black Sea Deluge, could be the inspiration for the great flood stories of the past, including the one in the Book of Genesis. That two geologists contend a real flood could be tied to a story in the Bible was not without some controversy in the academic community—and, of course, among believers. But leaving aside any biblical implications, their geological evidence for the disaster itself is solid. And, like the torrent that roared through the Strait of Gibraltar millions of years earlier, there was an upside to it; the merging of the Black and Mediterranean Seas opened up a critical nautical link stretching from Asia to the Atlantic Ocean. Today the Bosporus Strait is one of the world’s busiest shipping channels, with freighters sailing from the once-landlocked Black Sea to ports around the globe.

About 200 years ago, North America’s Great Lakes, the largest expanse of freshwater in the world, remained essentially isolated from the Atlantic Ocean. For thousands of years, the five inland seas wrapped by more than 10,000 miles of shoreline (islands included) sat cloistered in the middle of the continent. The four “upper” lakes—Erie, Huron, Michigan and Superior—lie some 600 feet above the level of the ocean, which made them unreachable from the Atlantic by boat. Much of that elevation is gained at the dolomite cliffs that are Niagara Falls, over which the collective outflows of all those lakes tumble on their way into Lake Ontario and from there down the thundering St. Lawrence River on their rush to the ocean.

Like the plugs of land that once isolated the basins that are now the Mediterranean and Black Seas, erosion has been having its way with Niagara Falls. It is expected the falls will disappear in about 50,000 years—which is to say, geologically speaking, pretty soon. When that happens, the cliffs that have for millennia separated the upper Great Lakes from the Eastern Seaboard will be gone. All that will remain is a fast-flowing, ever-eroding riverbed that will draw the lakes, every day, one step closer to sea level. How this all precisely plays out in terms of perhaps opening a nature-carved sailing route between the middle of the continent and the ocean is a matter of geological conjecture that won’t be answered for eons—an unbearably long period for the 19th- and 20th-century Great Lakes politicians and businessmen who were not content to leave the lakes as they had found them, as isolated inland seas upon which giant cargo boats could float from one Midwestern city to another, but never out to the ocean.

Their idea was to finish the job nature started when the last glaciers carved out the Great Lakes basins 10,000 years ago. Their dream was to create, by the hand of man, a North American “Fourth Seacoast,” thus flexing the Midwest’s burgeoning manufacturing might across the globe, prying open new markets in far-away cities and squeezing from them all manner of exotic bounty. They lusted for their own Mediterranean, for their own Strait of Gibraltar or Bosporus to emerge, but they were not willing to wait for such a natural disaster to unfold.